With Miley Cyrus at No. 1 on the Billboard Hot 100 with "Wrecking Ball," a song with some of the greatest buzz for a video in quite a while, it seems like a good time for a refresher on how the Hot 100 is tabulated, doesn't it?

As we wrote in January when YouTube data was added to the Hot 100's equation: "Generally speaking, our Hot 100 formula targets a ratio of sales (35-45%), airplay (30-40%) and streaming (20-30%)."

Of course, that's an overall target for 100 songs each week. That mark can change week-to-week. This week, though, the Hot 100 breaks down in line with the formula's intent: sales, 39%; airplay, 34%; and, streaming, 27%.

And, week-to-week, some songs show largely along those percentages, while others skew noticeably toward any of the chart's three metrics.

Let's look at a few, starting with "Wrecking Ball."

This week, points for the Hot 100's leader stem 50% from streaming, 43% from sales and just 7% from radio airplay. No surprise: the song drew a whopping 14.3 million U.S. streams in the chart's tracking week, according to Nielsen BDS. (The No. 2-streamed song, Katy Perry's "Roar," garnered 7.3 million.) "Ball" ranks at No. 3 on Digital Songs with 301,000 downloads sold, according to Nielsen SoundScan. Conversely, as airplay for "Ball" is just beginning, its low Hot 100 points percentage reflects its No. 31 spot on Radio Songs (via 38 million all-format audience impressions, according to BDS).

Last week, which reflected the first week of streaming following the song's video premiere, the Hot 100 ratio for "Ball" was even more streaming-driven: 64%, streaming; 34%, sales; 2%, airplay. The cut's monster 36.5 million U.S. streams in the chart's tracking period produced the high percentage.

Perry's new digital single "Dark Horse," featuring Juicy J, meanwhile, has been released as a teaser track from her album "Prism," due Oct. 22. It's not being promoted to radio and has no official videoclip. Thus, as it debuts on the Hot 100 at No. 17, an almost monopolizing 99% of its points are from sales; it sold 194,000 downloads in its opening week, good for a No. 4 start on the Digital Songs chart.

The more established "Roar" (No. 2 on the Hot 100), which has been promoted to radio for close to two months and has been accepted at mainstream and adult top 40 and adult contemporary, lines up much closer to the Hot 100's average ratio: 43%, sales; 31%, airplay; 26%, streaming. It's No. 1 on Radio Songs (159 million) and No. 2 on Digital Songs (301,000) and Streaming Songs (7.3 million).

Another hit, like Cyrus', due mostly to streaming, and even more so? Ylvis' novelty track "The Fox," which makes tracks running 25-13 as the Hot 100's top Streaming Gainer this week. With it at No. 3 on Streaming Songs (7.1 million), 75% of its Hot 100 points are from streams. Almost the rest of its sum is from sales; it debuts at No. 22 on Digital Songs with 60,000 in its first week. The song sports almost no airplay, although that could change now that Warner Bros. has begun promoting it to pop radio.

And, a song driven largely by airplay? Maroon 5's "Love Somebody," at No. 26 after peaking at No. 10, shows 67% of its points thanks to radio, with 19% from sales and 13% from streaming. As a fourth single from an album that's been available for a year, it's logical that sales and streaming lag behind the song's activity at radio, with the band a consistent presence at pop and adult formats long after the buzz of an album release. It ranks at No. 11 on Radio Songs and No. 59 on Digital Songs (while ranking just inside the 100 most streamed songs of the week).

I've *stolen* this - there's loads of queries around "instant grats" at UKMIX, so thanks to *Bré over at Buzzjack, here are some FAQ's around "instant grats"...

1. What is an 'instant grat'?

On iTunes, almost all albums are added as a pre-order a couple of weeks to a couple of months before release. (Why this is when digital albums have infinite stock is a different matter, but that's just the way it is). In an increasingly popular trend, many artists make songs available to download off the album tracklist before the album comes out - these songs are not given a 'single release', it's just like cherrypicking but a bit early. This song will automatically download when you pre-order the album and is thus called an 'instant grat' (short for 'gratification'). Sometimes more than one song is available as an instant grat from the same album.

2. What are the chart rules regarding instant grats?

Before the start of this year, no instant grats were allowed to chart at all. This led to awkward situations like Coldplay's 'Paradise' being excluded from the chart for six weeks when it would have been comfortably top 40. The OCC were prompted to change their mind when David Bowie's 'Where Are We Now?' was looking like a #1 contender that could have been excluded from the chart. (In the event, it ended up at only #6, but that's besides the point). However, the rules have only changed for when there is ONE instant grat track from an album. If there is more than one, only one of those tracks will be able to chart. This is usually the first one to be made available but is officially the one that the record label 'nominate' as the one chart eligible instant grat.

3. But wait, these are free downloads, surely they should be ineligible?!

This is a common misconception. Instant grats are not free at all - if you pre-order an album with an instant grat attached, it will immediately charge you 99p (or £1.98 or £2.97 etc. depending on how many tracks there are) for the instant grat track and the rest will just be charged when the album comes out. In addition, these songs *can* be downloaded separately without pre-ordering the entire album.

4. But if they can be downloaded separately, why can't all instant grats chart? Can't they just only count the separate sales?

Well, theoretically they can, but the leading theory is that they are just too lazy to chase Apple down for the split sales info. It's easier for them to just exclude songs entirely than only count some of their sales. (This isn't a problem for when there's only one instant grat because in this case album pre-orders are counted as sales for the songs).

5. If they charge 99p for the instant grat and then the rest of the album later, isn't that the same as just buying the album?

It is, yes, but by the same logic purchasing a pre-album single that isn't an instant grat and then taking advantage of the 'Complete My Album' feature means you didn't technically buy the single at all. Just because it's automated doesn't make it any different.

6. Aren't single sales deducted from their total when 'Complete My Album' is used?

This does happen in other countries (leading to the hilarious week where Taylor Swift sold -83,000 copies of 'We Are Never Ever Getting Back Together' in the USA) but as far as observational evidence shows, the OCC does not deduct single sales for the use of 'Complete My Album'. This might just be another case of them being lazy.

7. So how come only certain artists are restricted to one single charting and others aren't? If Lady Gaga is only allowed to chart with 'Applause', then how come One Direction are allowed in with both 'Best Song Ever' and 'Story Of My Life'?

Whether or not more than one song can chart depends on how the record label goes about distributing pre-album singles and promo tracks. Lady Gaga did not release any 'singles' prior to the release of 'ARTPOP' - 'Applause', 'Do What U Want' and 'Venus' were all released as instant grats so only one of those ('Applause') is allowed to chart as per OCC rules. However, One Direction released 'Best Song Ever' as a single (well, an EP, but same thing) separate from the pre-order for 'Midnight Memories', then made 'Story Of My Life' available as an instant grat. This means both are allowed to chart. If 1D add any more instant grats to the 'Midnight Memories' pre-order than they will not be eligible to chart, unless the label decides to nominate them as the single instant grat instead of 'Story Of My Life' (which would lead to the hilarious situation of 'Story Of My Life' disappearing from the chart, possibly from #1. MAKE IT HAPPEN).

8. So will these other instant grat songs never be allowed to chart?

Instant grats will only ever be chart ineligible while they are still instant grats. As soon as the album they're attached to is released they will become eligible for the chart. This might mean they'll end up with a much lower peak than they may otherwise have managed (for example Katy Perry's 'Walking On Air' entered the chart at #80 when it would have been at least top 40 with ease had it been previously eligible), but from that point onwards there's nothing to be confused about.

9. Are their sales still tracked while they're ineligible?

Apparently, yes. Music Week revealed the sales for Lady Gaga's 'Do What U Want' in its first week of availability as a chart ineligible instant grat, so it does appear that the OCC track their sales but just don't allow the songs to chart.

10. Does this mean those sales will be added onto its official total even though they were 'ineligible sales'?

This remains unclear but it seems the answer to that is no. Chart ineligible sales do not seem to ever count towards a song's official total sales. (If they did Coldplay's 'Paradise' will be becoming a million seller soon - I'm just gonna go ahead and pretend it is one anyway regardless of what the OCC say).

11. Okay now I'm just confused. Eminem DID release singles and he DID chart, but now he's suddenly ineligible? What's up with that?

In this particular case, the OCC's rules are showing how ridiculous they can sometimes be. Eminem did not put up a pre-order for his album 'The Marshall Mathers LP 2' until one week before its release. Three singles were released from the album before this - they were all separate single releases and therefore all of them were eligible to chart. However, when he put up the album pre-order, all of the singles were deleted from iTunes and all three - as well as a new track, 'The Monster' - were added as instant grats instead. As such, all 3 will now be excluded from the chart until the album release (which will incidentally be exactly one week, meaning 'Berzerk', 'Rap God' and 'Survival' will have a one week gap in their chart runs where they vanished from the entire top 200 before suddenly returning almost back where they were before. That'll be a fun one to explain to people in the future looking back at the charts of October/November 2013). 'The Monster' is the new 'nominated' instant grat song so is able to chart.

12. Is anything going to be done about this?

Sadly it appears the answer is no. We'll just have to hope that record labels realise these are the rules and stop releasing in ways that make tracks ineligible. Or, yanno, hope that they don't change at all, if you're someone who'd rather not see 4 Eminem songs in the top 40. But that's a different matter.

And if we have a single (for example "Too Hot" by Kool And The Gang), which was released in 1979, but certified as gold only in May 1989, it is for shipment 500 000 copies? What about "Crocodile Rock" by Elton - certified as gold (1 000 000) already in 70s, but later updated to Platinum certification, but only after January 89... It means the shipment figure is still 1 000 000? Thanks.

And if we have a single (for example "Too Hot" by Kool And The Gang), which was released in 1979, but certified as gold only in May 1989, it is for shipment 500 000 copies? What about "Crocodile Rock" by Elton - certified as gold (1 000 000) already in 70s, but later updated to Platinum certification, but only after January 89... It means the shipment figure is still 1 000 000? Thanks.

If a single certified Gold before January 1989 doesn't get a new Platinum award (like several Elton John and Kool & The Gang singles) then it's net-shipment was not 1-million and so it was not upgraded and must be considered a 500,000 seller.

Before january 1989 the certifications were based in gross shipments and the label would get the Gold award before the returns came in and that's why many years later, when the returns are obviously already known, those old Gold are not new Platinum.

One example is Michael Jackson's "I just can't stop loving you", it was Gold in 1987 but when Epic upgraded all MJ singles in 1989 the single "I just can't stop loving you" was not upgraded to platinum and this means its returns brought its net-shipments to below 1m copies and so it must considered a 500,000 certified seller.

a little note about albums (not singles) just for info :awards were also given when the albums met "manufacturer's dollar volume" at a certain percentage of the suggested selling price depending on the award (still going on now) . Some albums might have sold 500k (for ex.) or more but if they didn't meet that dollar percentage level, then they would not get the award. and viceversa, if an album sold , say, 420k or less but they more than made the money percentage, they would get the award. singles, a diff thing though on a personal note, i've heard of many artists that didn't want those certs so much because that would mean they should pay more taxes

I think this question is correct in this forum..can I ask why some countries like Argentina, Iceland,Slovakia or Bulgaria do not publish their certificationsWhere are the cerrtifications now published in Greece??in which chart is based the singles?same question for Turkey?and the slovenian album chart is official...why is not included in IFPI LIST??I hope someone can give me an answer....thanks in advance.....